In a Next Generation-Passive Optical Network (NG-PON) system, a plurality of Time-Wavelength Division Multiplexing Channels (TWDM CH) exist, each TWDM CH having at least one Uplink Shared Channel (US CH) and a Downlink Shared Channel (DS CH); each TWDM CH has, at least, a transceiver apparatus containing a receiver, a transmitter and corresponding MAC processing logics, similar to an OLT in an era of a traditional Time Division Multiplexing (TDM) PON, for processing; and transceiver apparatuses of different TWDM CHs may be integrated in a PON line card or may also be distributed in different PON line cards.
In a multi-wavelength TWDM PON system, it is necessary to support switching of an ONU in different TWDM CHs based on a great diversity of demands. For example, it is required that an OLT port is energy-saving (when there are few users, a user working on a TWDM CH corresponding to a certain OLT transceiver apparatus is adjusted into other TWDM CHs in a wavelength switching mode, thereby closing an idle OLT transceiver apparatus to achieve an energy-saving effect). For example, in a fault handling process of an OLT, a certain ONU is adjusted into an additional TWDM CH from an initial TWDM CH so as to judge a tuning ability and the like of the ONU. In a tuning process of the ONU, the communication of a currently-working TWDM CH transceiver apparatus is interrupted substantially, and a wavelength is adjusted to establish communication with a target TWDM CH transceiver apparatus. Consequently, communication channels and information interactions are needed between the currently-working TWDM CH transceiver apparatus and the target TWDM CH transceiver apparatus to guarantee mutual understanding and service configuration continuity, so as to enable the ONU to still work normally after being switched. The difficulty and complexity of communications and information interactions are different in different implementations of transceiver apparatuses. That is, if OLT transceiver apparatuses are all integrated inside a line card or even a component, the abovementioned communications will become internally implemented mechanisms without intercommunications; but if OLT apparatuses are scattered in different line cards or even different machine frames, these communications will need to be transmitted via an external network, and if these TWDM CH transceiver apparatuses are provided by suppliers of different manufacturers, it is necessary to research how to guarantee mutual understanding therebetween.
However, effective communication channels and information interaction logics are not provided for such communications in a currently existing TWDM PON standard and technical research.